The 15-year-old boy arrested in connection with five family members' deaths was charged Thursday with the murder of his parents and three of his siblings.

A 15-year-old boy has been charged in connection to a Fall City shooting that happened Monday, that left five dead.

Because of his age and nearly two decades of legal precedent that requires courts to treat children differently from adults, the 15-year-old boy accused in a mass shooting near Fall City will have a far more complicated court case than if he were even a year older.

A 15-year-old boy is accused of shooting and killing five of his family members, then staging the scene to appear as if his brother had shot the family, according to charging documents from the King County Prosecuting Attorney's Office.

The boy said his 13-year-old brother had killed their family and “taken himself out,” and that he was currently hiding in the bathroom.

A 15-year-old boy was charged with murder three days after he allegedly shot his parents and three young siblings to death in a bloody scene inside their lavish Washington state mansion. Prosecutors charged the teenage gunman — who was not identified due to his age — on Thursday with five counts of first-degree aggravated murder and one count of first-degree attempted murder,